The invention relates to an open-end rotor spinning device and, more particularly, to such a device comprising a spinning rotor rotating at high speed in a rotor housing subjected to low pressure and closed by a covering element, a single motor-driven opening cylinder rotating in an opening cylinder housing, and an at least two-part fiber guiding channel.
As described in numerous patent documents, for example German Patent Publications DE 198 00 402 A1 or DE 198 59 164 A1, open-end rotor spinning devices have a spinning rotor, which rotates during the spinning process at a high speed in a rotor housing subjected to low pressure. The rotor housing, which is open per se toward the front, is thus sealed in an air-tight manner during the spinning process by a covering element, into which a replaceable channel plate adapter is let. The covering element generally also has bearing brackets for an opening cylinder and for a fiber band feed cylinder. The covering element is connected so as to be movable to a limited extent to an associated spinning box housing via a pivot pin, which is arranged orthogonally to the axes of rotation of the opening cylinder and fiber band feed cylinder, the spinning box housing, for example, having the bearing and the drive for the spinning rotor. The individual fibers combed out from a feed fiber band, e.g., a sliver, by the opening cylinder are conveyed in such open-end rotor spinning devices via a so-called fiber guiding channel to the rotating spinning rotor and spun by the latter to form a thread which can be continuously drawn off.
The open-end rotor spinning devices described in the above patent documents have two-part fiber guiding channels. In other words, an input-side channel section is arranged in a receiver of an opening cylinder housing, while an output-side channel section is arranged inside the replaceable channel plate adapter, which is positioned in a corresponding receiver in the covering element. During operation, the channel plate adapter, which can be replaced when necessary and is fixed in a precise position in the receiver of the covering element and which, apart from the output-side channel section of the fiber guiding channel, also has a hole to fix a thread draw-off nozzle, reaches with a tower-like attachment into the rotating spinning rotor.
In conjunction with open-end rotor spinning devices, it has furthermore been known for a long time that in order to be able to produce open end yarns of good quality, certain boundary conditions, in particular with respect to the mutual arrangement and dimensioning of the spinning elements have to be fulfilled. The design and arrangement of the orifice region of the fiber guiding channel, in particular the spacing of the orifice to the fiber slide face in the spinning rotor, for example, have a not insignificant influence on the yarn quality which can be achieved. In the interests of optimal spinning results, it is therefore advantageous to allocate a suitable channel plate adapter to each spinning rotor, in particular according to its diameter. This means that in general a change of the channel adapter plate also takes place when an exchange of the spinning rotors is carried out, for example in the course of a yarn batch change.
It is also known that the fiber feed onto the fiber slide face of the spinning rotor can be positively influenced by a corresponding design of the fiber guiding channel. For example, the output-side channel section of the fiber guiding channel can be configured in such a way that its centre longitudinal line differs from a straight line.
In other words, the output-side channel section of the fiber guiding channel arranged in the channel plate adapter is either, as described in German Patent Publication DE 195 44 617 A1 curved or has, as stated in German Patent Publication DE 102 10 895 A1, an angled center longitudinal line. According to German Patent Publication DE 102 10 895 A1, an insertion piece is to be inserted into the output-side channel section of the fiber guiding channel, for example, in such a way that the centre longitudinal line of this channel section is angled. It has been found that owing to the curvature or the angled configuration of the output-side channel section, the fiber transport on this channel section and the feeding of the fibers onto the fiber slide face of the spinning rotor can be improved.
From German Patent Publication DE 198 36 066 A1, it is also known to arrange an input-side channel section of a fiber guiding channel connected to an opening cylinder housing and an output-side channel section of the fiber guiding channel arranged in a channel plate adapter in such a way that the centre longitudinal lines of these channel sections are arranged inclined at an angle. Such an arrangement of the channel sections of a fiber guiding channel has also proven advantageous for the producible yarn quality, in particular when the angle between the centre longitudinal lines of the channel sections is matched precisely to the existing yarn and/or spinning parameters.